Process for regenerating a solid desiccating agent



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4 PROCESS FOR REGENERATING A SOLID DESICCATING AGENT Filed Jan. les,1943v Wn-000 Wamv vision of aprooessin Patented May 4, 1948 PRQCES; S.YFORLREGENER fDESIQCATING i vVlillia1.1 .E- llerdem Keohi gTow-nshiv,Sedgwick `County, Kans., assjgnor to Globe/Oil &-Rening ompany,"Wichita, tKans., acer-poration of -AnPlieationI-lanuaty 16, 1943,Serial No- 472,574

This invention relatestoapiooess iorreeenereting ardesioeatine agent.andmorenertionlarly to a proeessfor degeneratie a.solid,desieoetirieagent of the water adsorption typense for 'the removal ofdissolved:water from .low boiling `hydrocarbon oils- I The process oftliisinventionis partieularly osefill for .regenerating a, desieeatineasentthat Y is `used 4-f0.1 the .remotal of f small quantities: of

dissolved ,water Atroni hydrocarbon oils nrior to Ythe time thatthehydrooatbonoilsare passed into transportation pipe lines. Thesmall .olla.titles of water normally .founddissolved in certain .hy-

drocarbon oils, such ,as lgasoline, kerosene,

straight-run distillatel tracked distillate., toto., may have atendeiteytoooridense within atrans- 4portation pine lil-.1ebeoalise..ofthe-relativelyzlow temperatures thatmay Joe ren.eolliitered therein. lThis, oondensed .water `leasa i tendency to -eaiise i eorrosion in`pinelimes- -ltiis well l known thattlie dissolved water eootentfof .tee,nydtooarloon .oil

een be reducedibylpassiriethe,oil overasolid adsorbent 11n-er1 oil esottreated water cdroplets Will-riot :have a tendeaoyto e dense-olpreoipi- `tate in the lpipeline The nated therein. llt isan oleieetA@athis invention lto provide aI-meansofor.-reaotvating, revit/if ing ior i regenerating La solid.fzilesiccating agent A,Wflgiich `may beusedior ,.reduoins thedissolved water content of :hydroearloon .oils.prior l.to the :time that they .are Ipassed .into l:.trans,portationn.pipe lines. I i t VIt is a furtherobjectof` this-inventiontoeprovide.a proces for reeeneeatirtathe sollddesioeatingfagent-VfundensuehconditionsV that ,atmos- -;pher io oxygeniortother-eesfislnotintrodueeddi- `reotly'into thenipe line A ifurther objectof-`hishinvention is =tllecinjoagent Vis thoroughly washeddiinathe ytionstep to removei-anyiresidues-that-,may have been deposited utherein -by`the passage fof ythe hydrocarbon Y oil tbeing -Adesiooatedtherethrough- 'A furtherandfadditiorialobjectof this invention is 4-to lprovide etsolid. desiooating agent ref generation prooesstwherein theagent is ;dr.ed with a hot inertfsasfwltioh is r.s ,-11lost'.1r1tiallycapable of reacting with the desiccating agent i .l e of -corrosion intheloipe line maytthereby e` ubstantially .det creased or the oorrlosionmay y Joe ...entirely elimi- 2 or of -polymerizing or formi-ngundesirable liquid or solid productswhen it is contactedwith asoliddesiceating agent.`

Further and additional objects will appear from -ths specication, theaccompanying drawing and-the appended claims.

In accordance With one embodiment of this invention, vthesoliddesiccatingagent used inthe rem-oval of dissolved `Water fromhydrocarbon oils may be-regeneratedbyfirst washing the desiccat- Aingagent with a lowboiling hydrocarbon liquid, `pass-ing `a stream lof`gasinto contact with the Washed desiccating agent at an elevatedtemperature whereby to remove Water therefrom in the '1&5l

4 iccating agent `With `a low boiling lnonaqueous form of a vapor,andtbereafter flooding said desliquidto prevent the Acontact `of gasestherewith prior to the time thattthe desiccating agent Vis4reused-Afortliie removal of `dissolved -Water from the hydrocarbon oilbeing processed. If desired, the desiccating agentmay be disposed insuitably enlarged chambers, and anumberof these cham- -bers maybearranged in series -sothat a desired degree of dissolved AWater'rernovalfrom-the oil being treated may be effected. In -accordance with thepresent invention, one ofi--the-chambers czontaining the desiccatingagent `may be cut iout of thel series and subjected to the regeneration,process while `the hydrocarbon oil being treated is passed through theremainder of thechambers i in series. ,maybe used for Washing'thedesiccat-ing agent in Any `low boiling hydrocarbon liquid4thecl'iarnioerpriorto the actual regeneratingstep.

j itoweveiq, any other loyv boiling hydrocarbon oilAVstraight-runnaphtha having a boiling point between 500 and 400 `F. maysuitablybe used.

maybe nsedjforthewashing step, itbeingjpref- Merablhetliat all theconstituents thereof be evapotable so thata residue will not b eleft onthe desiccating agent during the regeneration step.

vI {l1ein,ert gas used for expelling the nadsorbed Water fromthedesieeating agent may suitably loe naturellgas- .Howevery other gases,suoh as eombiistion eases, still eases, oraekine eases and Vltlnetlile,.maybe used. Natural gas ispreferred beoeuse it cheap .and is.substantially `free from dust, sulfur dioxide, hydrogensulde, oxygen,

polymerizable Qlnic hydrocarbons, and @ther able eodstituents However,carbon dioxide or nitrogen` or other inert gas ,fzre' from the chamber2.

undesirable products could be used with equal efficiency. In accordancewith one embodiment of this invention the hot regenerating gas, afterhaving been contacted with the solid desiccating agent, may be coooledto condense and separate the water vapors therein and reheated andrecycled to the desiccating agent in order to effect further waterremoval. This process therefore requires only small amounts ofregenerating gas which may be continually used in the process.

For a more complete understanding of this invention, reference will nowbe had to the accompanying drawing wherein is shown diagrammatically anapparatus for carrying out the process of this invention. Essentiallythe apparatus shown in the drawing comprises three chambersv 2, 4 and 6arranged in series, each having disposed therein a solid substance, suchas dried silica gel or activated alumina, capable of absorbing dissolvedwater from a hydrocarbon oil which may be contacted therewith. Thesechambers are connected in series-by suitable piping, and are furtherarranged so that any one of the chambers may be cut from the oiltreating system for purposes of regeneration while the oil to bedesiccated is passed through the remaining chambers of the series.

The oil from storage containingsubstantial amounts of dissolved water ispassed from storage through the pipe 8 to the treating chambers, and theoil from which the desired amount of dissolved water has been removedafter passage through the chambers is discharged from the desiccatingsystem to the transportation pipe line I6. Gas for the regeneration orrevivication of the desiccating agent is heated in a gas heater I2, andafter passage through the chamber being regenerated (2, 4 or 6) passesthrough the gas cooler I4 in order to condense the' water vapor whichseparates in the Water separator I6. If desired, the entire oildesiccating system can be by-passed through the pipe I8 so that the oilfrom storage may be passed directly to the pipe line I6 withoutcontacting the solid desiccating agent disposed in chambers 2, 4 and '6.As shown in the drawing, a number of pipes controlled by suitable valvesare provided for cutting the charn- 4bers 2, 4 and 6 into and out of thesystem in the manner to be described and for effecting the desiredwashing and treatment of the desiccating -agent to effect the desiredregeneration or revivication thereof.

In carrying out this process the oil to be desiccated may be passed fromstorage through pump 26, valve 22, pipe 8, pipe 24, valve 26, into Thechamber 2 has disposed therein a, solid desiccating agent, preferably ofthe adsorption type, such as silica gel or activated alumina, forremoving at least a portion of the vdissolved water normally present inthe oil. The

therein, the oil passes continuously from the top vof the chamber 4 tothe transportation pipe line I0 -through pipe 48, valve 42, pipes 44 and46, valve 48, pipe 56, pump 52, pipe 54, valve 56, pipe 58, and valve6I).

, y While the oil is being passed through the Yld icwcgriling chambers 2and 4 as above described,`

75 naphtha contained therein flows directly into the chamber 6 has beencut out of the system by suitable valve manipulation. The oil remainingin chamber 6 is drained therefrom to a suitable sump (not shown) througha pipe 62, a Valve 64, and a pipe 66. After the oil has been withdrawnfrom the chamber 6, the chamber is then lled by suitable valvemanipulation with a straight-run naphtha contained within storage tank68. The naphtha flows from the storage tank 68 to the chamber 6 throughpipe 10, valve 12, pipe 14, valve 16, and the pipe 62. Whilebeingemptied of oil and lled with naphtha, the chamber 6 is vented throughpipe 18, valve 80, pipe 82', and pipe 66. The naphtha serves to wash outany nonvolatile hydrocarbon residue that may be present on thedesiccating agent within the chamber 6. The character of the naphtha issuch that it contains substantially no nonvolatile constituents so thatno residue is left deposited on the solid adsorbent during thesubsequent heated gas treatment. In the event that it is desiredcontinually to pass the straight-run washing naphtha through the chamber6 for a period of time, then the naphtha passes from the upper portionof the chamber through pipe 18, Valve 80, and pipe 82, into the sumppipe 66. After the washing of the desiccating agentin the chamber '6 bythe naphtha, the excess naphtha is then drained from the chamber 6through the pipe 62, the valve 64, and the sump pipe 66.

After washing the desiccating agent -in chamber 6 and draining of thewash naphtha through pipe 62, valve 64 and pipe 66, a stream of naturalgas heated in the gas heater I2 is passed through pipe 84, valve 86 andthe pipe 62 into the bottom of the chamber '6. The hot gas serves tovaporize the water adsorbed on the surface of the solid desiccatingagent. The gas and water vapors pass from the chamber 6 through the pipe18,

valve 88, and pipe 90 to the gas cooler I4 wherein the water condensesfrom the gas. The co-ndensed water is removed` from. the gas` in vthewater separator I6, and the gas is recycled through pipe 92, gascompressor 94, valve 96, and pipe 98 to theY gas heater I2 and reused asdescribed above. Pipes |60 'and |02, controlled by suitable valves, maybe employed for introducing and withdrawing gas from the system. Y

After the desired degree of reviviflcation or regeneration of thedesiccating agent in chamber 6 has been effected, cool gas may be cycledthrough the chamber in order to cool the desiccating agent. This maybeaccomplished by cutting the steam supply oi of the gas heater I2 andcycling the gas as above described. After the desiccating agent in thechamber 64 has been cooled somewhat, a fresh charge of straight-runnaphtha from the storage tank` 68 is introduced into the chamber 6 inorder further to cool the desiccating agent therein. e This charge ofnaphtha in chamber 6 covers or floods the solid desiccating agent andserves to prevent air from contacting the regenerated solid desiccatingagent prior to the time that the chamber 6 is cut back into thedesiccating system. Itis desired not to pass air over the desiccatingbed because of its probable deleterious effects on the bed and oilretained therein; and it is desired also to keep all gas, including air,out of the transportation pipe line. Hence the gas remaining in chamber6 after regeneration is completely displaced with naphtha. When thechamber 6 is to be cut back into the desiccating process, suitablevalves are manipulated so that the charge of straight-run pipe line i9with the oil that is passed through the system. This naphtha should haveproperties (particularly in respect to color and boiling point) whichwill permit of its being pumped directly into the pipe line with thehydrocarbon oil being treated without lowering the speciiications of thelatter below tolerance.

When the solid desiccating agent in chamber 2 or in chamber 4 needsrevivifying or regenerating, these chambers may be cut out of the systemby the manipulation of suitable valves and regenerated in the samemanner as described in the foregoing in connection with chamber il. Whenthe chambers are connected in series in the manner described above, itis desirable that the first chamber into which the oil to be treated.

is owed is the one which has the highest amount of adsorbed watertherein so that the desiccating agent last contacted by the oil beingtreated is the agent which has been most recently revivifled orregenerated.

While in the drawing three desiccatingr chambers have been shown anddescribed, this number is of course not essential in accordnace with theteachings of this present invention. For example, any number of chamberscontaining desiccating agents may be used and they may be connected inseries or in parallel, or partly in series and partly in parallel, asdesired.

While a particular embodiment of this invention is shown above, it willbe understood, of course, that the invention is not to be limitedthereto, since many modifications may be made, and it is contemplated,therefore, by the appended claims, to cover any such modifications asfall within the true spirit and scope of this invention.

I claim:

1. In the art of transporting a hydrocarbon liquid through a pipe linewherein said liquid is passed through a body of a solid desiccatingagent for the removal of water dissolved in said liquid prior to theintroduction of said liquid into said pipe line, the process ofperiodically regenerating said desiccating agent which comprisesdiscontinuing the ow of hydrocarbon liquid through said body, washingsaid body of desiccating agent with a low-boiling hydrocarbon washliquid, passing a stream of a substantially noncondensible andnonoxidizing inert gas through said body at an elevated temperaturewhereby to remove water therefrom in the form of a. vapor, :floodingsaid body with a lowboiling liquid hydrocarbon to displace all of saidinert gas within said body to prevent the inclusion of gas within thehydrocarbon liquid when the desiccating agent is reused, and thereafterreestablishing the flow of said hydrocarbon liquid through said body ofdesiccating agent.

2. In the art of transporting a hydrocarbon liquid through a pipe linewherein said liquid is passed through a body of a solid desiccatingagent for the removal o@ water dissolved in said liquid prior to theintroduction or said liquid into said pipe line, the process ofperiodically regenerating said desiccating agent which comprisesdiscontinuing the ow of hydrocarbon liquid through said body, drainingexcess amounts of said liquid from said body, washing the drained bodywith a low boiling hydrocarbon Wash liquid, draining excess wash liquidfrom said body, passing a stream of a substantially noncondensible andnonoxidizing inert gas through said body at an elevated temperaturewhereby to remove Water therefrom in the form of a vapor, flooding saidbody with a low boiling hydrocarbon displacement liquid to displace allof said inert gas within said body to prevent the inclusion of gaswithin the hydrocarbon liquid when the desiccating agent is reused, andthereafter reestablishing the flow of said hydrocarbon liquid throughsaid body of desiccating agent whereby said displacement liquid and saidhydrocarbon liquid pass together into said pipe line.

3. In the art of transporting a hydrocarbon liquid through a pipe linewherein said liquid is passed through a body of a solid desiccatingagent for the removal of water dissolved in said liquid prior to theintroduction of said liquid into said pipe line, the process ofperiodically regenerating said desiccating agent which comprisesdiscontinuing the flow of hydrocarbon liquid through said body, drainingexcess amounts of said liquid from said body, washing the drained bodywith a low boiling hydrocarbon wash liquid, draining excess wash liquidfrom said body, passing a stream of a substantially noncondensible andnonoxidizing inert gas through said body at an elevated temperaturewhereby to remove water therefrom in the form of a vapor, thereafterpassing a cooler stream of said gas through said body to lower thetemperature, then iiooding said body with a low boiling hydrocarbondisplacement liquid to displace all of said inert gas within said bodyto prevent the inclusion of gas within the hydrocarbon liquid when thedesiccating agent is reused, and thereafter reestablishing the iiow ofsaid hydrocarbon liquid through said body of desiccating agent wherebysaid displacement liquid and said hydrocarbon liquid pass together intosaid pipe line.

4. The process recited in claim 3 wherein said gas is natural gas.

. WILLIAM E. PERDEW.

REFERENCES CITED The following references are of record in the nie oithis patent:

UNITED STATES PATENTS Number Name Date 1,431,982 Richter et al. Oct. 17,1922 1,794,538 Palmer et al. Mar. 3, 1931 1,946,748 Lemmon et al. Feb.13, 1934 2,273,350 Fry et al. Feb. 17, 1942. 2,323,524 Downs July 6,1943

